Warren is opposed, on religious grounds, to abortion rights, gay rights, stem-cell research, and euthanasia. In 2004, he described these issues as "nonnegotiable" and "not even debatable."Those "absurd reasons," by the way, entailed Warren conflating same-sex marriage with polygamy, incest, and rape.
What's more, just this month, Warren supported Prop. 8 in California for absurd reasons.
Apparently, Obama and Warren are personal friends, which doesn't actually mitigate the selection so much as make me wonder if Obama's been dropped on his head.
I understand that Warren isn't going to be driving policy, that he's only leading a prayer at the inauguration (and why there is a prayer at the presidential inauguration is a whole other post), but I also know that there are, literally, thousands of other religious leaders from multiple religions and Christian denominations, who aren't anti-choice, anti-gay, and anti-science, whose presence at the inauguration wouldn't be a sharp stick in the eye to progressive women and GBTQ men, and all their allies, so it would have been really fucking nice if any one of them could have been selected for this prominent opportunity instead of Rick bloody Warren.